Initial release: self-hostable APT repository server and CLI

urapt is a self-hostable APT repository server with a companion CLI for
pushing and managing Debian .deb packages.

Server (urapt-server):
- REST API + APT endpoint, SQLite storage (pure-Go modernc driver, no CGO)
- .deb files stored content-addressed on disk, reference-counted for dedup
- Server-managed RSA-4096 OpenPGP signing key (ProtonMail/go-crypto)
- APT indices (Release/InRelease/Packages[.gz/.xz]) generated on demand
  from the DB, cached in memory, signed with the server key
- Full APT model: repositories -> distributions -> components -> architectures
- Bearer-token auth for REST; HTTP Basic auth for private-repo APT reads
- First registrant becomes admin; repo-scoped permissions
  (read/write/read-write/admin) plus owner and server-admin roles
- Multipart package push with control-field extraction, list/show/delete,
  pool serving, blob ref-count cleanup
- Audit log

CLI (urapt):
- register/login/logout/whoami, token management
- repo/distro/component/arch CRUD, member management
- push/pull/ls/show/rm for packages
- apt-config helper that emits apt setup commands (key, sources.list,
  auth.conf for private repos)

Packaging & docs:
- Dockerfile (multi-stage distroless), docker-compose.yml, sample config
- README quick start, architecture overview, config reference, security notes
- PLAN.md design blueprint, CHANGELOG.md, GPL-3.0 LICENSE
- GitHub Actions CI (test, lint, cross-build for linux/darwin amd64/arm64)
- Makefile release target producing static binaries + tarballs + checksums

Tests cover the data-access layer, auth/permission checks, APT index
generation, .deb parsing, GPG signing, the REST API, and the typed API
client. Verified end-to-end on a Raspberry Pi (arm64) pushing and installing
a real package.

.github/workflows/ci.yml

@@ -0,0 +1,83 @@
+name: CI
+
+on:
+  push:
+    branches: [main, master]
+    tags: ['v*']
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Test (linux/amd64)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+          cache: true
+      - name: gofmt
+        run: |
+          unformatted="$(gofmt -l .)"
+          if [ -n "$unformatted" ]; then
+            echo "::error::gofmt would modify the following files:"
+            echo "$unformatted"
+            gofmt -d $unformatted
+            exit 1
+          fi
+      - name: go vet
+        run: go vet ./...
+      - name: go build
+        run: go build ./...
+      - name: go test
+        run: go test -count=1 ./...
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+          cache: true
+      - uses: golangci/golangci-lint-action@v6
+        with:
+          version: latest
+
+  cross-build:
+    name: Cross-build (${{ matrix.goos }}/${{ matrix.goarch }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+          - goos: linux
+            goarch: arm64
+          - goos: darwin
+            goarch: amd64
+          - goos: darwin
+            goarch: arm64
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+          cache: true
+      - name: Build urapt-server
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+          CGO_ENABLED: '0'
+        run: go build -o /dev/null ./cmd/urapt-server
+      - name: Build urapt CLI
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+          CGO_ENABLED: '0'
+        run: go build -o /dev/null ./cmd/urapt